Hoping for some ideas. Recently installed a 2x4 tunnel ram on my Chevy gasser. (mild pump gas 383 Stroker, 4:86 gears). Made 4 passes at Thompson last weekend (gas pedal broke on fourth pass), and all four passes were at or near 8.2 @ 84 mph. After that, the car fell off to low 13's and gained only another 3-7 mph at the finish. I'm happy with 1/8 times on this motor but I'm obviously suffering after half track. Conversion charts show that the car should be turning around 12.7 @ 110 or maybe better if I can also improve the 1/8 numbers.
Right now we suspect that the Holley mech fuel pump may not be keeping pace with dual carbs, and this is the first time I've run dual carbs. Plan is to switch to an electric pump, but any ideas or suggestions as to whether or not we're on the right track appreciated. (Plugs show no evidence of rich or lean condition, good even color).
Dave

Hoping for some ideas. Recently installed a 2x4 tunnel ram on my Chevy gasser. (mild pump gas 383 Stroker, 4:86 gears). Made 4 passes at Thompson last weekend (gas pedal broke on fourth pass), and all four passes were at or near 8.2 @ 84 mph. After that, the car fell off to low 13's and gained only another 3-7 mph at the finish. I'm happy with 1/8 times on this motor but I'm obviously suffering after half track. Conversion charts show that the car should be turning around 12.7 @ 110 or maybe better if I can also improve the 1/8 numbers.
Right now we suspect that the Holley mech fuel pump may not be keeping pace with dual carbs, and this is the first time I've run dual carbs. Plan is to switch to an electric pump, but any ideas or suggestions as to whether or not we're on the right track appreciated. (Plugs show no evidence of rich or lean condition, good even color).
Dave

If your tuning by reading the plugs, don't drive the car back to the pic then check them. If you can, tow the car back to the pit or check them at the end of the track. Of course this is easier with a HEMI than engines with the plugs right next super hot headers!